Sand blast tank apparatus



F b- 28, 9 3- w. A. ROSENBERGER 1,399,528

SAND BLAST TANK APPARATUS Filed Aug. 18, 1928 3 Sheets-Sheet -1 n I"? nFeb. 28, 1933. w. A. ROSENBERG-ER 1,899,528

SAND BLAST TANK APPARATUS Filed Aug. 18, 1928 3 Sheets-Sheet 2 Feb. 28,1933.

W. ROSENBERGER .SAND BLAST TANK APPARATUS Filed Aug. 18, 1928 3Sheets-Sheet 3 dummy Patented Feb. 28, 1933 UNITED STATES PATENTOFFICEF- WILLIAM A. ROSENBERGER, oFnAGE-Rsrown, MARYLAND, Assrenon 'roranenoan' CORPORATION, or HAGERSTOWN, MARYLAND, a conrona'rron orMARYLAND SAND BLAST TANK APPARATUS Application filed Aug ust 18, 1928.Serial No. '300,578

connected as to be also utilized as means for r separating the abrasiveparticles from the air when the pressure in the tank is dlscharged forany purpose, as in refilling with abrasive,

and the device may further include means it for protecting'the separatorelement from the action of the abrasiveas it is projected against theseparator by the air as it escapes from the tank through the separator.

The apparatusalso includes improvedmeans for controlling the dischargeof the abrasive and regulating the abrasive flow w th extreme accuracy,the same being adapted to prevent clogging of the abrasive as it passesthrough the regulating passages or orifices.

In the accompanying drawings Figure 1 is a side elevation of a smallsand blast tank of the portable type equipped in accordance with theinvention.

Figure 2 is a top plan view of the same;

Figure 3 is a vertical section through the bottom of the tankandcontroller valve casting on the axis of the controller valve;

Figure 4 is a section on the line Jr-4 Figure 3.

Figure 5 is a top plan view of the right hand 5 end of the controllervalve as seen in Figure 3,

the same being shown in this figure as disconnected fromthe tank.

Figure 6 is a perspective view of the eccentrioally apertured valvebushing. Figure 7 is a diagrammatic plan of the abrasive passage andvalve, the valvecasting being broken away. 7

Figure 8 is a fragmentary perspective view of the controller valveremoved from the valve seat. 1 V

Figure 9 is a vertical cross section showing the water and abrasiveseparator. V

Figure 10 is a horizontal cross section on the line 1010 of Figure 9.

Figure 11 is a plan of the controller valve,

the portion at the left being broken away and I shown insection ontheline 1111 of Figure 3.

Referring to the drawings by numerals, each of which isused to indicatethe same or similar parts in the differentfigures, the machine,'asshown, comprises a. sand blast pres sure tank 1 which, as-shown, ispreferably of the small portable variety to which the features of theinvention are particularly adapted, though they are capable ofmoregeneral application. Y J y The, tank 1 is provided with a fillervalve 2at the top for the admission of abrasive, air under pressurebeing-suppliedby way of an air pressure pipe 3 to the. separator 4,which 1 v separator 4 is connected by a short nipple5 to the inside ofthe tank near the top and-by a drop pipe 6 to the abrasive mixing andcontrolling valve 7 atthe side by wayof a passage 8, see particularlyFigure 4, the con-. troller valve, in turn, being connected in'a mannerto be described, to the bottom of the tank at 9 to receive abrasivetherefrorin The controlling and mixing valve 7 is, in turn, connected byway of a flexible hose 10 to a suitable abrasive projecting nozzle .11.

. Referring more particularly to the details of the structure, the valve2 for the admission of abrasive is, in the preferred form of theinvention shown, held in position by a screw handle 15 which has athreaded engagoment with a yoke 16, which yoke is removably secured inposition on the tank by means of belts or studs 17 having heads 18spaced upwardly above the tank, the yoke having open slots to receivethe bolts.

The slot 19, Figure 2, in the form of the invention shown, is open atone endof the yoke and the slot 20 is open at the side near theother'end. The handle '15 has a screw threaded shank 21 which has athreaded engagement with the yoke and the end of the screw may engagethe cover in any suitable manner.

The air pressure pipe 3, in the form of the invention shown, is providedwith a three way valve 25, see Figure 1 which, in the differentpositions of the ,val'vefconn'ects the pressure pipe 3to the tank and tothe mixer valve 7 through the separator 4 and in the other position ofthe valve closes the pressure pipe 3 and connects the tank 1 and themixer valve 7 to the open air by way of the separator 4. 1

The separator 4: comprises a separator member 27,. also referred to as aseparator barrel, in the form of a tubular member which, in thepreferred form of the invention shown, is composed of several layers ofWire cloth. This barrel or separator member, as shown, extends the fulllength of the separator casing 28. It encloses the end of the air inlet29 at the top inside the casing 28 and the end of the drip discharge 30at the bottom, the end referred to being also at the inside of thecasing. The casing 28, as shown, consists of a tubular member 31enclosingthe separator member. This is closed at the top by a cap 32through the center of which the connection 29 is passed,-and it isclosed at the bottom, in the form of the invention shown, by a fitting33 which may be also referred to in its complete form as a cap, butwhich, in the form of the invention shown, is a reducing fittingenclosing with its upper portion the lower end 34 of the tubular member28 of the casing, the said fitting being, in turn, closed at its lowerend by a plug 35 which is hollowed out to receive the lower end of theseparator barrel 27 and is further bored and tapped at 36 at its lowerend at the center to receive the drip cock 37. The separator barrel 27is encircled opposite the. nipple 5 which connects the separator to thetank and the connection 38 which connects the separator to the drop pipe6 which leads to the mixing valve by a shield shown in theform of aplate ring 39 which protects the-separator member or barrel 27 or thewire cloth portion thereof from the abrasive particles which wouldotherwise be projected against the separator member when the tank isbeing emptied of compressed air through and by way of the separator, asalready indicated and as more fully hereinafter described. 7

It will be understood that whenair is admitted from the'pressure pipe 3through the nipple 29 at the top of the separator, it is dischargedwithin theseparator inside the separator barrel 27 and passing outwardlythrough the multiple screen the moisture is rubbed out ofthe air bycontactwith the screen. This effect is increased by the tendency toexpansionof the air from the pressure in the pipe 3 to the pressurewithin the tank 1 causing cooling and condensation.

The moisture thus collected runs down inside the tubular separatormember 27 and collects at the bottom of the casing 28 in the cap orfitting 33 from which it is removed at the will of the operator byopening the drip cook 37.

The reverse operation of the separator is of considerable importance.When new abrasive is to be supplied the three-way valve 25 is firstturned to release the air under pres sure in the tank through theopening 26 leading from the valve to the outside air, the pressure pipe.3 is at the same time closed. In passing through the separator, which itenters from the tank mainly by way of the nipple 5, and drop pipe 6 andthe fitting 38, the air is projected directly against the shield 39 andowing to the high velocity which it attains and to the boiling of theabrasive in the tank due to the release of the pressure, a

considerable amount of abrasive is carried by the escaping air into theseparator where it comes in contact with the shield 39 and isdepositedin the separator. Part of the abrasive thus deposited isreturned to the tank by the reverse air current during the subsequentfilling of the tank with air and any which accumulates innthe separatormaybe discharged by way ofthe bottom plug 35, which may be removed forthis purpose.

By the action-of the separator 4, removing the abrasive from the airduring the discharge of the latter-from the tank prior to filling, thedestructive action of the abrasive on the three-way valve 25 throughwhich it must pass in the absence of the separator, is practicallyeliminated and in this way an extremely troublesome sourceofreplacements is removed or, at least, the necessity for replacements isso reduced as to have substantially this effect.

Other features of importance relate to the construction and operation ofthe mixing and controllingvalve and other details at the bottom of themachine which contribute to the production of accurate control and easyadjustment of the stream, making it possible to useextremelyfine'nozzles down to those as small as three sixty-fourths ofan inch. The features of this part. of the machine also include anarrangement whereby it is made possible to handle a fine stream ofabrasive, as described, without clogging.

The construction also includes a new form of valve which not onlycontributes to accuracy of adjustment, but to the length of life of theassembled device, in that it not only presents to the abrasive a shutofi edge of material which withstands the abrasive action to the bestadvantage, but provides for four of such edges which can be usedalternatively, increasing the life of the valve member by acorrespondingmultiple. The construction also provides for theinstantaneous replace of the valve member.

In the form illustrated, the tank is flanged at the bottom at 40surrounding the discharge through the tube.

any suitable manner, as by means'of bolts 42 passed throughthe flange 40and through suitable ears 43 on the mixer valve, member 41, seeparticularly Figures 1, 3 and 5.

In the construction shown the discharge opening 9 is slightly enlargedor chambered at 44 immedately below the mouth of'the opening 9 whichchamber 44 receives and accommodates the flow control bushing orapproach bushing 45, to be more particularly described. J

- The flange 40 is further chambered at 46 surrounding the chamberedportion 44 near the bottom surface of the flange 40. This chamber 46being wide and shallow to accommodate a gasket 47 between the flange 40and the controller valve casting 41. The mixer valve casting 41 isprovided near the bottom with a longitudinal air passage 48 which, asshown, and normally, is substantially horizontal.

This passage 48 is closed at one end at the left in Figure 3 and at theother end at the right it terminates in the air and abrasive mixturepassage 49, which discharges into the hose 10 which is connected to thefitting 50 which is seated in the mouth of the passage 49. Leading,downwardly into the abrasive ind air mixture passage 49 is the abrasivepassage 51 which, in the form of the inven-, tion shown, hasa reducingtaper downward ly toward the passage 49,.being intersected by theabrasive fiow valve chamber 52,- which chamber 52 is shownin the form ofa horizontal bore formed in the mixer valve member 41 which it entersfrom the left of the same as seen in Fi ure 3. Above the valve I b atesin the chamber 52 is a cylindrical'tubiular member, preferably formed,particularly as to its wearing surface, of high quality rubher. Thisvalve is secured to a valve operating shaft 56 which fits inside of thetubular,

valve member 55, being secured thereto to rotate therewith by means of apin 57 which extends diametrically through the shaft and The valve andshaft are surrounded near the open end of the chamber or bore 52 bypacking 57, which is separated from the tubular valve member 55 bywashers 58.. The packing and the valve and the shaft are, in turn, heldin position by the packing gland member 59 which is shown. in the formof a hollow plug which is apertured at (SO-to pass the shaft 56. Thegland member 59 is shown as provided with laterally extending arms 61,see particularly Figure 4, through which are passed bolts 62, seeFiguresBv and 4, which bolts are seated in the valve member41 at eachside of the bore 42. The gland member 59 enters the end of the bore 52,beingforced into close contact withthe packing and compressing the sarneby tightening of the bolts 62. The shaft 56 may be turned by means of anindicating wheel 64 which is secured to the end of the shaft in anysuitable manner, as bymeans of a pin 65, the wheel being preferablymarked with graduations66, see Figure 1, which cooperate withan'indicating pointer 67 on the valve member or casting 41 and thegraduations 66 are preferably arranged in four series or scales on eachside of two zero marks 74 indicating the two closed posit-ions of thevalve, as hereinafter de- 7 scribed. i The valve member 55 ispreferably'slotted at 70,:the slot being adapted to register in the openposition of the valve with the pas- I sage 51 formed inthe casting,41forthis purpose, it'being understood that t seat chamber 52 intersects thepassagi51an d divides it into upper and lower portions or.

openings 51 and 51f. By rotating the'valve 55 to the position in whichthe slot70 regis:

ters with these openings, a passageway for the abrasive is opened fromthe tank 1 to the ne valve mixture or mixing passage 49.

In accordance withthe preferred construcion the slot 7 O is of the Itype, or otherwise formed to present one or more inclmed closing edges72. In the form of the invention shown, there are four of theseedges,two being presented at each of the opposite ends of the V shaped slot70.

As willbe noted from examination of the diagrammatic view, Figure 11,the passage 51 is preferably of rectangular cross section, be ing shownas elongated so thattheinitial opening formed by the intersection of theedges 72 with the cross section of the passage is triangular, asillustrated diagrammatically in Figure 7 by dotted lines 73. i

This illustration shows a distinct advantage incident to the inclinedclosing edges, particularly in connection with the rectangular passage51 having two sides parallel to the axis of the valve and two sides atright angles to it, in that it gives extremely fine regulation oradjustment as compared te would be given by closing edges parallel tothe sides of the passage 51 which, in the initial opening which wouldotherwise be the extreme minimum of adjustment, would give Such aslotwhen of less width ice 7 initial opening being triangular inoutline, can beadapted to pass an extremely small quantity of abrasive,the adjustment being capable of reduction to a point where a single line.of abrasive particles is passed through the opening at the minimumadjustment.

The construction shown, particularly in Figure 8, attains the extremelyimportant result that it presents four closin edges 72, either one ofwhich may be passed across the opening 5l'ahead of the remainder of thevalve, inthe opening'or closing operation.

It will be easily understood that in the op-' eration of this valvethere are twofully closed positions one hundred and eighty degreesapart. By marking these zero points'at 74 on the scale 66 and graduatingthe scale on four quadrants, i. e., on each side of each of theseopposite marks 74k, a set of graduations is provided corresponding toeach of the edges 72 whereby either of them may be used as the advanceclosing edge in opening and closing the valve and its position, i. e.,the degree of opening of the valve may be indicated on the scale bymeans of the pointer 67.

The flow control bushing or approach bushing 45, previously referred toas seated in the chamber 44,53, is, in the form shown, novided with apassage which at the top registers with the opening 9 and whichterminates at the bottom in a relatively small eccentrically locateddischarge opening 76. The bushing, see particularly Figure 6, is formed-with diametrically opposite key notches-7T which are adaptedto engagethe key projection 7 8011 the valve member 41 so that the bushing can beseated in two diametrically opposite positions of adjustment, beingraised for which purpose the member 41 must be disconnected from thetank 1 and rotated through an angle of one hundred and eighty degreesfrom one position to the other.

In the position shown, the discharge opening 76 is spaced by aboutone-third of the diameter of openin '76 out of registration relativelyto the passage 51and in'the opposite position in which the other notch2'7 engages the key projection 78, the discharge opening-76 willregister accurately with the passage 51. This gives what may be termed aprimary flow control of the abrasive from the tank 1 to the valve.

- A further object of the construction shown as to the bushing l5 andthe passage therethrough, consists in the means for preventingcloggingof the opening 76, 51, by and with abrasive. This isaccomplished by making the incline of the tapered passage 75 steeper onone side, i. e., at 79, than it is on the other side at whereby theparticles approaching the discharge opening 76 are given a differentrate of speed, i. e., faster on the side 79 and slower on the side 80,so that the tendency to clog is overcome by the tendency thus createdto-rotate the particles on one side the fiow is controlled about theparticles onthe other side. The rolling orrotating effect thusaccomplished prevents, or greatly reduces, the tendency to clog theopening.

The operation has been quite fully explained in connection with thedescription of the'machine. WVhen air is admitted to the tank from thepressure pipe 3 the moisture is removed by rubbing as the air expands orpasses outwardly through the multiple screen 27, enteringithe tank byway of the connection-5 and being supplied to the mixer valve by way ofthe drop pipe 6 and lateral passage 8, F igured, leading to the airpassage 48 and the mixing passage 49.

An important result is attained when the airisdischarged from the tankto reduce the pressure therein in order to admit a new supply ofabrasive. For this purpose the threeway valvei25 is turned to a positionin which the top or" the separator is connected by the passage 29 and aoutside air by way of the three-way valve, the pressure side of thethree-Way valve 25 being closed. This causes the air to leave'the tankby way of the passage 5, the air from the tank being discharged into theseparator against the shield 39 byway of the fitting or nipple 5. Aconsiderable amount of abrasive is carried by the air which is thusdischarged, due to the boiling of the abrasive in the-tank incident tothe drop of pressure therein. This abrasive is separated from theout-flow ing air-by the separator barrel 27 so that air which ispractically free of abrasive is dis charged by way of the fitting 29 tothe air pressure pipe 3, being released through the three-way valve 25.

An important difficulty with this type of apparatus in the past hasresulted from the quick destruction of the three-way valves due to thenecessity for passing abrasive through it when the tank was emptied ofair. This difficulty is completely overcome by the use and arrangementof the separator in the manner described.

Regarding the control valve. mechanism, primarily by the adjust? ment ofthe flow control bushing 45. In this way the discharge opening'76 of thebushing is either placed in registration with the passage 51, giving themaximum flow, or it is placed off-center, as shown in Figure 3,whereby'the flow of abrasive is reduced in the first instance to aboutfifty percent of the maximum, depending on the adjustment of theabrasive flow valve 52 to be most used.

The eflect of the variation of incline on the diiferent sides of theopening 75 in the bushing and 7 9 and 80, has been fully explainedportion of the pipe 3 to the whereby the particles on the opposite sidesThe fine adjustment of the abrasive stream,

or more particularly of the supply of abrasive l fed to the mixing valveto be mingled with the air blast, is obtained by means of the abrasiveflow valve 52 which also serves as a shut-0E valve to give a completecessation of the supply of abrasive and a double seal of the passage 51.V

In either one of the zero positions, i. e., when either of the zeropoints 7a on the indicator wheel 64 is in line with the pointer 67,

slot with a resulting fine regulation of the stream at and near theminimum flow, has

also been fully explained.

Still another important point resides in the easy and convenient mannerin which the valve may be removed and replaced. This is accomplished byremoving the bolts 62 which hold the packing gland 59 around the valveshaft 56 when the valve with the packing 57 and the shaft 56 may beremoved. A new valve may be immediately substituted on the shaft 56 byremoving the pin 57 and the new valve as instantaneously replaced.

I have thus described specifically and in detail a sand blast apparatusembodying the features of my invention in the preferred form in orderthat the nature and operation of the same may be clearly understood,however, the specific terms herein are used descriptively rather than ina limiting sense, the

scope of the invention being defined in the claims.

What I claim as new and desire to secure by Letters Patent is:

1. The combination with a sand blast tank of a mixing valve, a passageconnecting the tank to the valve to supply abrasive to the valve fromthe tank by gravity, a tapered bushing having an eccentric openingfOI'IIl. ing part of said passage the bushing having a restricted areaabout its bottom portion, means for reliei ing the pressure on theparticles immediately below said restricted area, means for positivelylocating the bushing in a plurality of positions whereby the relation ofthe passage in the bushing to the remainder of the passage is variedvarying the size of the opening and regulating the flow of abrasive fromthe tank to the valve and a separate control valve for furtherdetermining and regulating the supply of abrasive to the mixing valve.

hence the supply of abrasive 2. The combination with afsand blast tankand an abrasive mixing valve with a passage leading the abrasive fromthe tank to the valve by gravity, a bushing having an opening with adownwardly reducing taper forming part of said passage, the lower end ofthe opening being eccentri'cally located, the tapered portion having asteeper angle of inclina-tion at one side than] the other, and means forlocating-the bushing in a plurality ofpositions, varying as toangularlyof the bushing about a vertical axis, in one ofwhich the lowerend of the opening in the bushing registers with the remainder of thepassage more-nearly than in another position, where by the effectivesize of the opening and the. flow of-the abrasive maybe regulated.- 1

8. The combination with sand blast tank and an'abrasive mixingvalve, thestructure including a passage leading the abrasive from the tank to thevalveby gravity, the passage comprising a stationary restricted openingand a bushing having anopening with a downwardly reducing taper, thelower end of the opening being eccentrically lo cated and the taperedportion having a steep er angle of inclination at one side than theother, and means for locating the bushing in a plurality of positions inone of which the lower 'end of the opening in the bushing reg= isterswith the restricted opening more nearly than in another position wherebythe ef-,

fective size of the opening and the flow of the abrasive may beregulated, the variation of the incline tending to prevent clogging ofthe opening.

4. The combination with a sand blast tank of amixing valve and a passageleading abrasive from the tank to the valveand means for regulating theflow of abrasive through the passage comprising a cylindrical valvemember of rubberlike material, a cylindrical seating chamberintersecting the passage, so that the plug extends transversely to saidpassage, means adapted for manual engagement to rotate the valve memberat the will of theoperator, the end portion of the valve occupying theportion of the chamber which intersects the passage and said portion ofthe valve having a V slot, which in one angu lar position of the valveregisters with the passage, in which position the valve is open, the Vslot in another position of the valve standing at right angles to the.directionof the passage in which position the valve is closed,

advancedacross the passage to regulate the size of the same.

5. The combination with a sand blast tank the flow of abrasivecomprising a sectioniof cylindrical 1 tubing of rubbenlike material, acylindrical seating A chamber intersecting the ;passage,thetubularisection'fitting the said :chamber which is arranged so that; thetubuilar section extends transversely of the passage, means-adaptedIEOIl I I1 2LI1U2Ll engagement torotate the valve member, said manuallyengageablevmeans having a pin adapted to enter the tubular sectionaxially (from one end, said 'pin being provided With-means for,lfastenlngthc tubularisection and-positioning i-tzagainstrotationrelatively thereto causing I it to rotate therewith; the-end portion ofthe:

- valve opposite-to the manually engageable -member' which occupiesthesportion ofvthe I "chamber which intersects the passage having---.ters-.with-the passagcuin which'position the a V slot whioh-imoneangularepositionsrlegisvalve is open zthe- V slot: in another positionlflofsthe valveextending at' night angles to: the

position :of: thepassage; in which position the valveis closecl5,ltheintersection of the Vaslot Withthe-cylindrical surface of the-valveproviding four. inclined edges citherone of which 5:ma--be:advanced-acrossthe assa etore u- Si-gn-edby me at. I HagerstovvnMaryland,

this :27 daylof Ju1 ,;1928.

